Transmission-line switch



Sept. 30, 1958 w. 1 WILSON 2,854,543

TRANSMISSION-LINE SWITCH 2 Sheets-Sheet 1 Filed Jan. 26, 1956 Fig. 2

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William J. Wilson INVENTOR.

Sept. 30, 1958 Filed Jan. 26, 1956 W. J. WILSON TRANSMISSION-LINE SWITCH 2 Sheets-Sheet 2 r a am $75", Z A

I5 I 31; 4b l n H F2 r!) al 0 -290 -2 6 Cf 1 5005 O William J. Wilson b INVENTOR.

United States Patent TRAN SMISSION -LINE SWITCH William J. Wilson, Nashua, N. H., assignor to Sanders Associates, Incorporated, Nashua, N. H., a corporation of Massachusetts Application January 26, 1956, Serial No. 561,404

Claims. (Cl. 200-87) The present invention is directed to switches for highfrequency transmission lines and particularly to such switches for use with planar-type transmission lines.

Flat-strip or planar transmission lines are now well known and widely used in the art. The fiat-strip or planar form of transmission line is not only used for the purpose of conducting high-frequency energy from one point to another, but is used for directional coupling, antennas, impedance-matching devices and many other types of apparatus. Intercoupling of apparatus of these types introduces problems of switching the planar transmission line in or out of a circuit or between two auxiliary pieces of high-frequency apparatus. In the past this has been done by utilizing conventional coaxial-cable switching devices, coupled between the planar-transmission-line apparatus to be switched. This procedure is not only wasteful in power due to normal coupling losses, but is also expensive and undesirably cumbersome. It is therefore a purpose of the present invention to provide a planar-transmission-line switching device which does not have the undesirable features and deficiencies of a conventional coaxial switch.

It is therefore an object of the present invention to provide a new and improved switch for planar high-frequency transmission lines which is extremely simple.

It is another object of the present invention to provide an inexpensive switch for planar high-frequency transmission lines.

It is a further object of the present invention to provide a small, fiat-type of switch for planar high-frequency transmission lines.

It is additionally an object of the present invention to provide a switch for planar high-frequency transmission lines which has the form factor of such lines.

In accordance with the present invention, there is provided a switch for planar, high-frequency transmission lines. The switch comprises a pair of elongated, outer, planar conductors providing a pair of ground planes, a pair of elongated dielectric members and a pair of elongated, inner, planar conductors narrower than the dielectric members and disposed in parallel with and mounted on the dielectric members in insulated, spaced relation between the outer conductors. One of the inner conductors is displaced longitudinally with respect to the other having one end thereof overlapping an end of the other conductor. A control device is mechanically coupled to one of the dielectric members for flexing one ofthe inner conductors with respect to the other inner conductor to make or break electrical contact therebetween,

For a better understanding of the present invention, to-

' gether with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

. In the drawings:

Fig. 1 is a perspective longitudinal, sectional, represen- 2,854,543 Patented Sept. 30, 1958 tation of a switch for planar high-frequency transmission lines in accordance with the present invention;

Fig. 2 is a longitudinal, sectional view of the switch of Fig. 1;

Fig. 3 is a longitudinal, sectional view of a modified form of the switch in accordance with the present invention; i

Fig. 4 is a longitudinal, sectional view of another modified form of the switch in accordance with the present invention;

Fig. 5 is a cross sectional view of the switch of Fig. 4; and

Fig. 6 is a longitudinal, sectional view of another modified form of the switch in accordance with the present invention.

Description and explanation of operation of switch of Figs. 1 and 2 Referring now to Figs. 1 and 2, the switch includes a pair of elongated, outer planar conductors providing a pair of ground planes. More particularly, these outer, planar conductors are the top and bottom conductors 10 and 11. These conductors may be long, relatively narrow sheets of conductive material such as copper or silver and are kept in spaced relation with respect to each other by means of the dielectric material 12 and 13 sandwiched between these conductors.

Additionally, the switch includes a pair of elongated, planar inner conductors 14 and 15 disposed in parallel with and in insulated spaced relation between the outer conductors 10 and 11. The dielectric members 12 and 13 sandwiched between the outer conductors and the inner conductors maintain the inner conductors in spaced relation with respect to the outer conductors. Preferably, each of the inner conductors is mounted by means of printed-circuit techniques or otherwise on a dielectric base which is wider than the conductor mounted thereon. Thus, the inner conductor 14 is mounted on the dielectric 12, while the inner conductor 15 is mounted on the dielectric material 13. In the cavity 16- formed in the dielectric material 13 a dielectric fluid or gas such as air, or a vacuum, fills at least part of the space between the inner and outer conductors 15 and 11, respectively. One of the inner conductors is displaced longitudinally with respect to the other and has one end thereof overlapping an end of the other. Thus, the inner conductor 14 is in the left-hand portion of the space between the inner conductors 10 and 11, the inner conductor 15 is in the right-hand portion and the inner conductors 14 and 15 overlap each other in the area of the cavity 16.

The switch also includes means for flexing one of the inner conductors with respect to the other to make or break contact therebetween. More particularly, as represented in Figs. 1 and 2, a dielectric push button 17 is positioned in contact with the inner conductor 15 in the area of the cavity 16. The button 17 is spring loaded by means of spring 18 to exert no force on the conductor 15 until pressure is applied to the button. The conductors 14 and 15 are normally in contact and are separated only by depressing the button 17.

It is apparent that the switch of Figs. 1 and 2 is essentially a section of planar transmission line in which sufficient room is provided for motion of two center conductors with respect to each other soas to make or break electrical contact. When inserted in a planar transmission line the switch just described requires little more volume, and more important, thickness than that needed for the transmission line. The motion of the inner conductors with respect to each other need be no more than A of an inch and therefore over-all thickness of the switch sandwich need be no more than A of an inch. The width dimensions of the switching section are the same as the planar transmission line sections coupled thereto. The improvements over a cumbersome, expenslve and complex coaxial switch are obvious.

Description and explanation of operation of switch of Fig. 3

The switch of Fig. 3 is similar to that described with reference to Figs. 1 and 2 except it is a single-pole, double-throw switch whereas the switch described .with reference to Figs. 1 and 2 was a single-pole, single-throw switch. In view of the similarity, the same elements in both switches are identified by identical reference numerals.

The switch of Fig. 3 includes an additional center conductor 20 separated from the center conductor 14 by means of dielectric material 21 and from the bottom conductor 11 by the dielectric 13. The switching center conductor 15 is arranged to be switched to make contact either with the center conductor 14 or the additional center conductor 20. The addition of the center conductor provides a sandwich-type of construction in the left-hand portion of the switch which includes from top to bottom the outer conductor 10, the dielectric spacer 12, the center conductor 14, the dielectric spacer 21, the center conductor 20, the dielectric spacer 13 and the bottom outer conductor 11. A pair of dielectric pushbuttons 22 and 23 are employed. The switching operation of the switch of Fig. 3 is similar to that described with respect to the switch of Figs. 1 and 2 except for providing double throw and needs no further discussion.

Description and explanation of operation of switch of Figs. 4 and 5 The switch of Figs. 4 and 5 is similar to that of Figs. 1 and 2 in many respects and therefore similar elements are identified by identical reference numbers. The switch of Figs. 4 and 5 differs from that of Figs. 1 and 2 in the structure of the flexing center conductor, the mechanical linkage to effect motion of the flexing center conductor and in the arrangement used to control the linkage.

As is more evident in Fig. 5 the flexing center conductor 15 is mounted on a wider strip of dielectric material 25, the edges of which are fitted into slots in the side members 26 and 27 of a rectangular switch-control frame 28. The side members 26 and 27 extend through the planar, transmission-line switch without making electrical contact with any of the conductive members. A shaft 29 which is an integral part of the frame 28 is encircled by a solenoid winding 30 electrically connected to a'suitable source of power through a control device such as an electrical switch (not shown). A biasing spring 31 is positioned between a lower bar 32 of the frame 28 and the lower conductor 11 to establish the neutral position of the frame 28.

Description and explanation of operation of switch of Fig. 6

The switch of Fig. 6, in many regards, is similar to that described with reference to Fig. 3 while incorporating the electromagnetic control of Figs. 4 and 5. In view of this similarity, the same elements in these switches are identified by identical reference numerals.

The switch of Fig. 6 includes a pair of switching sections, specifically those in the cavities 16a and 16b. The switching member 15 is supported between the external conductors 10 and 11 by means of dielectric blocks 37' and 38. A coaxial connector is provided for-coupling electrical energy to the switching member 15 if such is desired.

The operation of each switching section ofthe switch of Fig. 6 is similar to that of the switch of'Fig. 3 provided with a solenoid control such as described with reference tothe switch of Figs. 4 and 5. The switching member may be so controlled by the solenoids 30a and 30b as to connect conductor 14a. with either conductor '4. 14b or 20b or to connect conductor 20a with conductor 14b or 20b. Energy may be supplied by any of conductors 14a, 20a, 14-1) or 20b and switched to other conductors in the manner just described or by the connector 35 and then switched into any of the conductors 14a, 20a, 14b and 20b.

While there have been described what are present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is, therefore, aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A switch for planar high-frequency transmission lines, comprising: a pair of elongated outer planar conductors providing a pair of ground planes; a pair of elongated dielectric members; a pair of elongated inner planar conductors narrower than said dielectric members and disposed in parallel with and mounted on said dielectric members in insulated spaced relation between said outer conductors, one of said inner conductors being displaced longitudinally with respect to the other and having one end thereof overlapping an end of said other; and a control device mechanically coupled to one of said dielectric members for flexing said one of said inner conductors with respect to said other to make or break electrical contact therebetween.

2. A switch for planar high-frequency transmission lines, comprising: a pair of elongated outer planar conductors providing a pair of ground planes; 8. pair of elongated dielectric members; a pair of elongated inner planar conductors narrower than said dielectric members and disposed in parallel with and mounted on said dielectric members in insulated spaced relation between said outer conductors, one of said inner conductors being displaced longitudinally with respect to the other and having one end thereof overlapping an end of said other; and a magnetically activated control device mechanically coupled to one of said dielectric members for flexing said one of said inner conductors with respect to said other to make or break electrical contact therebetween.

3. A switch for planar high-frequency transmission lines, comprising: a pair of elongated outer planar conductors providing a pair of ground planes; a pair of parallel elongated inner planar conductors disposed in parallel with and in insulated spaced relation between said outer conductors, each of said inner conductors being shorter than said outer conductors and having an exposed end; another elongated inner planar conductor disposed in parallel with and in insulated spaced relation between said outer conductors and displaced longitudinally with respect to said pair of inner conductors and having one exposed end overlapping said exposed ends of said pair of inner conductors; and means for flexing said other of said inner conductors with respect to said pair of inner conductors to make or break electrical contact therewith.

4. A switch for planar high-frequency transmission lines, comprising: a pair of elongated outer planar conductors providing a pair of ground planes; a pair of elongated dielectric members; a pair of elongated inner planar conductors narrower than said dielectric members and disposed in parallel with and mounted on said dielectric members in insulated spaced relation between said outer conductors, one of said inner conductors being displaced longitudinally with respect to the other and having one end thereof overlapping an end of said other; and a fork-like control device having a pair of tines individually connected to opposite sides of one of said dielectric members for flexing said one of said inner conductors with respect to said other to make or break electrical contact therebetween.

5. A switch for planar high-frequency transmission lines, comprising: a pair of elongated outer planar conductors providing a pair of ground planes; a pair of elongated dielectric members at least one of which is thin and flexible; a pair of elongated inner planar conductors narrower than said dielectric members and disposed in parallel with and mounted on said dielectric members in insulated spaced relation between said outer conductors, one of said inner conductors being displaced longitudinally with respect to the other and having one end thereof overlapping an end of said other; and a fork-like control device having a pair of tines individually connected to opposite sides of said one of said dielectric members for flexing said one of said inner conductors With respect to said other to make or break electrical contact therebetween.

References Cited in the file of this patent UNITED STATES PATENTS Armstrong Sept. 23, Schreiner Nov. 25, Dorne Dec. 9, Beleskas June 7, Ellis et al. July 17, Miller et al Feb. 5, Kamm Nov. 29, Towle Dec. 27,

FOREIGN PATENTS Great Britain Sept. 22, 

